Bevacizumab + CHOP-Rituximab in Untreated Mantle Cell Lymphoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bevacizumab + CHOP-Rituximab in Untreated Mantle Cell Lymphoma (NCT00401817), a na phase 2 study. The primary outcome is Number of Participants With Toxicity.

2. Clinical Question

The central statistical question is descriptive: among the participants treated in this study, how many were recorded as experiencing the specified toxicity? The primary outcome is titled “Number of Participants With Toxicity,” and its description identifies reversible myelosuppression as the primary toxicity. Toxicities were graded using National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. The listed timeframe is 38 months.

The registry also names response rate and time to disease progression as secondary objectives, and lists overall response rate, progression-free survival, and overall survival as secondary outcomes. These outcomes address disease response and follow-up, but their numerical results are not reported in the registry record. The record also identifies prospective characterization of angiogenic profiles as a secondary objective; it does not give a result for that objective.

Because there is no separate control group, the study cannot make a like-for-like comparison between this regimen and another treatment. Its design can describe observations among participants receiving the regimen, but it does not isolate the effect of bevacizumab from the effects of rituximab-CHOP or other influences. The registry record does not report a comparative estimate for the primary safety question.

3. Trial Design

This is a completed Phase II study recorded as a single-group trial. The registry lists 11 participants enrolled and describes the condition as untreated mantle cell lymphoma. It records allocation as NA and masking as none. No randomized allocation or masked assessment is described, and there is no separate control arm in the record.

The study treatment arm received bevacizumab-R-CHOP. The regimen description specifies bevacizumab at 15 mg/kg on day 1 and standard-dose R-CHOP on day 3, for six 21-day cycles. The listed interventions are bevacizumab, rituximab, and CHOP. The study’s primary objective was to evaluate safety in patients with newly diagnosed mantle cell lymphoma. Secondary objectives concerned response rate, time to disease progression, and angiogenic profiles during treatment.

The study start is recorded as 2007-11, primary completion as 2011-07, and status as completed. These dates describe the registry timeline; they do not establish how long each participant was followed or whether every participant completed the planned treatment. The primary outcome timeframe is listed as 38 months, but the registry record does not explain the relationship between that timeframe and individual follow-up.

A single-group design is useful for describing outcomes observed in a treated cohort, but it does not provide a concurrent comparison for estimating what would have happened under another regimen. Differences from other studies could reflect differences in participants, treatment delivery, follow-up, outcome definitions, or chance. The registry record does not report an external or historical comparison as part of the primary analysis.

The registry lists four outcome measures and zero analyses. It does not report a detailed statistical analysis plan, a sample-size justification, interim analyses, or methods for handling missing observations. These omissions limit what can be concluded about the planned statistical framework and how the reported outcomes were evaluated.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Toxicity, measured over 38 months.

The primary endpoint is titled “Number of Participants With Toxicity.” Its description identifies reversible myelosuppression as the primary toxicity, and states that toxicities were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. The timeframe attached to the outcome is 38 months. The registry record does not report the primary endpoint’s observed count or its analysis.

A participant count is a descriptive way to summarize how many people experienced an event during the defined observation period. It differs from a count of all event episodes: a participant with repeated episodes may still contribute once to a participant-level endpoint, depending on the endpoint definition. The registry record does not give additional details about event recurrence, severity thresholds for inclusion in this particular endpoint, or how the observation window was applied to individual participants.

In general, safety endpoints are used to characterize adverse experiences during treatment and follow-up. A participant-level count can make the occurrence of a specified toxicity understandable, while grading criteria can help classify its severity. The choice of a defined toxicity is important because a broad safety profile can include events with different causes, seriousness, and clinical importance. The record identifies reversible myelosuppression as the primary toxicity, but does not provide enough endpoint-level results to describe its observed frequency or severity in this study.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the study question and design. This study is recorded as single-group, with allocation marked NA and masking listed as none. In general, a single-group study observes outcomes in participants who receive a treatment without assigning a concurrent comparison treatment. Its results can describe the cohort, but they cannot provide a randomized contrast between treatments. The registry record does not report a control group or a comparative effect estimate.

What does a participant count measure?

The primary endpoint is a count of participants with toxicity, with reversible myelosuppression identified as the primary toxicity. In general, a participant-level count answers how many people met the event definition, rather than how many separate episodes occurred. That distinction matters when events can recur. The registry record does not specify whether recurrent episodes were counted separately, nor does it report the observed count for the primary endpoint. The outcome timeframe is listed as 38 months, but details about individual observation periods are not reported in the registry record.

The description says toxicities were graded using National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Grading systems provide structured categories for recording severity. In general, consistent grading can make safety observations easier to classify and compare, but it does not by itself establish event cause. The record does not provide the primary toxicity’s grade distribution or explain how grades were incorporated into the participant-count endpoint.

How should uncertainty be understood?

In general, an estimate from a clinical study is subject to sampling variability: a different group of eligible participants might produce a different observed result. A confidence interval communicates uncertainty around an estimate under specified assumptions. Narrower intervals generally indicate greater precision, while wider intervals indicate less precision. An interval does not correct for a missing comparison group, incomplete outcome reporting, or bias in selection and measurement. The registry record does not report a confidence interval for the primary outcome.

For a binary outcome, analysts may describe the number of participants with an event and the number assessed. The registry’s primary outcome is framed as a participant count, but the result itself is not reported. No rate, test, or interval should be inferred from the study enrollment alone. In particular, an outcome count cannot be reconstructed from enrollment or from unrelated adverse-event summaries.

What do the planning assumptions represent?

In general, sample-size calculations use assumptions about an effect worth detecting, outcome variability, significance level, power, and allocation. The planning illustration associated with this analysis is described as using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. For time-to-event outcomes, the illustration is described as using a total number of events; other illustrations are described in participants per arm.

Those assumptions are planning conventions, not evidence that the trial used that design. The actual study is single-group, not a two-arm comparison. The registry record does not report the trial’s own sample-size justification or a planned effect size. Any planning illustration is therefore hypothetical and should not be interpreted as the study’s enrollment target, an observed result, or observed power. Sample-size planning is not the same as calculating power after seeing the study results.

Why does over-dispersion matter in general?

For count outcomes, some statistical models assume that variability follows a particular relationship to the average count. Over-dispersion means the observed variability is greater than that model expects. If it is ignored, standard errors may be too small and intervals or tests may appear more certain than warranted. This is a general issue for count-data analysis; the registry record does not report a count model, a dispersion assessment, or an analysis of recurrent events for this study.

What can the adverse-event summaries support?

The record lists 1 of 11 participants in the serious adverse-event count and 11 of 11 in the other adverse-event count for the study treatment arm. These are descriptive summaries. In general, adverse-event categories can differ in seriousness and scope, so counts in distinct categories should not be conflated. A participant may also experience more than one event, meaning event counts and participant counts are not interchangeable. The record does not provide enough detail to determine how categories overlap or to characterize all event episodes.

The record lists Prostate Cancer at 9.1% among serious-event terms. A listed term is a reported event description; without further attribution information it does not establish that treatment caused the event. The registry record does not report an analysis comparing event risk with another group.

Finally, the registry lists four outcome measures and zero analyses. It does not report the statistical methods used for the secondary outcomes, multiplicity procedures, missing-data methods, or analysis populations. These details are needed to judge whether estimates and tests followed prespecified procedures. Without them, interpretation should remain descriptive and tied to what the registry explicitly records.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Study Treatment Arm")
n      <- c(11)
events <- c(8)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Study Treatment Arm  11  8  72.7  39.0  94.0  43.4  90.3  42.8  90.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, including the primary toxicity outcome and secondary outcomes concerning overall response rate, progression-free survival, and overall survival. It also describes secondary objectives involving response rate, time to disease progression, and angiogenic profiles. The registry record does not report a multiplicity strategy, such as a hierarchy among outcomes or an adjustment for testing several hypotheses.

In general, when multiple outcomes are tested, the chance of obtaining at least one apparently unusual result can increase if each test is treated independently at a conventional threshold. A prespecified outcome hierarchy or multiplicity adjustment can address that issue, but the appropriate approach depends on the aims and analysis plan. Since no outcome analyses are reported, and the registry record does not describe a multiplicity plan, the impact of multiple testing cannot be evaluated.

Missing-data handling is also not reported in the registry record. The record does not say how participants with incomplete toxicity follow-up, missing assessments, or early discontinuation were handled. It does not identify whether outcome data were collected for all enrolled participants or whether any observations were excluded.

The analysis population is not reported in the registry record. It is therefore unclear whether the intended summaries were based on all enrolled participants, those who began treatment, those with an evaluable assessment, or another group. In general, different analysis populations can yield different estimates, especially when inclusion depends on post-enrollment events. Without a stated population and missing-data approach, the registry summaries should be interpreted as reported counts rather than as results from a fully specified analysis framework.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: prostate cancer (9.1%).

The adverse-event summary lists 1 of 11 participants in the serious adverse-event count and 11 of 11 in the other adverse-event count for the study treatment arm. These are participant counts in separate summary categories; the registry record does not provide enough detail to establish how the categories overlap or what event-level rules were used. The listed serious-event term is Prostate Cancer, with 9.1%.

These figures describe registry entries, not a comparison with another treatment group. A serious event is not necessarily caused by study treatment, and an event term alone does not establish causality. The record does not report additional attribution information, event narratives, or a comparative safety analysis. The Prostate Cancer listing should therefore be read as a reported term and percentage, not as a conclusion about treatment-related risk.

The primary safety objective focused on reversible myelosuppression, but the registry record does not report its observed participant count or grade distribution. The serious-event summaries should not be substituted for that primary endpoint. In general, safety interpretation benefits from knowing the event definition, timing, severity, attribution, and completeness of follow-up. Those details are not reported in the registry record for these summaries.

13. What the Result Does, and Does Not, Mean

The record supports a limited description of a completed Phase II study in which 11 participants with untreated mantle cell lymphoma were assigned to a single study treatment arm. The regimen description includes bevacizumab with standard-dose R-CHOP, delivered on the specified days over six 21-day cycles. Safety was the primary objective, with reversible myelosuppression identified as the primary toxicity.

The record does not report the observed primary toxicity result or a statistical analysis of that endpoint. It lists 1 of 11 participants in a serious adverse-event count, 11 of 11 in another adverse-event count, and Prostate Cancer at 9.1% among serious-event terms. These data are descriptive registry entries and do not establish that the regimen caused or prevented any event. They also do not answer the primary question about the frequency of reversible myelosuppression.

The secondary outcomes include overall response rate, progression-free survival, and overall survival, but numerical results are not reported in the registry record. There is no reported comparative estimate, confidence interval, or analysis result for those outcomes. A single-group study can document what happened in its cohort, but it cannot provide a randomized estimate of how outcomes differ from another treatment or from no treatment.

In general, the precision and interpretation of a study depend on its sample size, event frequency, follow-up, outcome definitions, analysis methods, and completeness of data. The registry record does not give enough information to evaluate these features for the primary endpoint. The sample-size planning assumptions associated with the analysis are illustrations, not evidence that the study had a two-arm design or that an effect was established.

Accordingly, the record describes the design, regimen, objectives, and some adverse-event summaries, but does not report enough outcome analysis to quantify the study’s primary safety result or its uncertainty. It should not be read as demonstrating comparative benefit or harm.

14. Why This Trial Matters Statistically

This study is statistically notable as a small, single-group Phase II investigation with a safety-focused primary objective. The record makes the intended clinical focus explicit: evaluating bevacizumab-R-CHOP in newly diagnosed mantle cell lymphoma, with reversible myelosuppression identified as the primary toxicity. It also lists disease-response and survival outcomes as secondary measures.

At the same time, the record illustrates why a clearly stated objective is not enough to support a complete statistical interpretation. The primary endpoint’s observed result is not reported, and the registry lists zero analyses. Without the endpoint estimate and its uncertainty, readers cannot assess how common the specified toxicity was in this cohort or how precisely it was estimated.

The single-group design is an important statistical boundary. It can describe the experience of participants who received the regimen, but it cannot provide a concurrent randomized comparison. That distinction matters when interpreting adverse events as well as disease outcomes: counts observed during treatment do not by themselves separate treatment effects from background events or other influences.

The registry’s listed serious-event summaries also show why event categories need context. The serious-event count, other adverse-event count, and primary reversible-myelosuppression endpoint are not interchangeable. Their definitions, overlap, timing, and attribution all affect what a count means, and the record does not report those details fully.

Finally, the planning assumptions associated with sample-size illustrations do not replace information about the trial’s own design rationale. A hypothetical two-arm planning framework is distinct from this single-group study, and no sample-size justification is reported in the registry record. The main statistical lesson is to distinguish descriptive cohort observations, planned analyses, and comparative evidence rather than treating them as equivalent.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation is incomplete outcome reporting. Although the primary endpoint is defined as the number of participants with toxicity and reversible myelosuppression is identified as the primary toxicity, its observed result is not reported in the registry record. The record also does not report a primary endpoint confidence interval or inferential analysis.

The study enrolled 11 participants and used a single-group design. In general, a small cohort offers limited precision, and the absence of a concurrent control prevents a like-for-like estimate of differences between treatment strategies. Observed safety events cannot be attributed to the regimen from this design alone.

The registry record does not report the analysis population, missing-data methods, individual follow-up, or how early discontinuation affected outcome assessment. Although the primary outcome timeframe is listed as 38 months, details of observation and censoring are not reported. These omissions make it difficult to assess whether outcomes were available consistently across participants.

The record lists secondary outcomes but does not provide their numerical results or analysis methods. It also does not report a multiplicity approach, a protocol-level statistical plan, or interim analyses. The listed adverse-event summaries lack event narratives and further attribution detail, and their relationship to the primary toxicity endpoint is not specified.

Finally, the record does not report the trial’s sample-size justification. Planning assumptions described for illustrative calculations should not be mistaken for the study’s design rationale or evidence of observed power. Together, these gaps limit assessment of precision, completeness, and the extent to which analyses followed prespecified methods.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Bevacizumab + CHOP-Rituximab in Untreated Mantle Cell Lymphoma — NCT00401817.
• Registry record last updated 2017-10-20; status last verified 2017-09.
• Results first posted 2017-10-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed Phase II, single-group study of bevacizumab with rituximab-CHOP in untreated mantle cell lymphoma. It lists 11 participants enrolled, no masking, and allocation marked NA. The regimen description specifies bevacizumab at 15 mg/kg on day 1 and standard-dose R-CHOP on day 3 for six 21-day cycles.

The primary objective was safety, with reversible myelosuppression identified as the primary toxicity and a 38-month timeframe listed. Secondary outcomes include overall response rate, progression-free survival, and overall survival. The record lists 1 of 11 participants in a serious adverse-event count, 11 of 11 in another adverse-event count, and Prostate Cancer at 9.1% among serious-event terms.

The primary endpoint result, secondary outcome results, and statistical analyses are not reported in the registry record. The record also does not report the analysis population, missing-data methods, multiplicity procedures, or sample-size justification.